BETA-GALACTOSIDASE AS A MARKER OF HSP70 PROMOTER INDUCTION IN DUNNINGR3327 PROSTATE CARCINOMA-CELLS

Hyperthermia is known to improve the response of tumors to radiation o r chemotherapeutic treatment when combined in multimodal strategies. T he cellular response to hyperthermia is associated with the synthesis of heat shock proteins (HSP). To study the stress response in prostate cancer we have developed a clone of Dunning R3327 rat prostate carcin oma cells stably transfected with a gene construct containing the E. c oli beta-galactosidase gene driven by the Drosophila HSP70 promoter. T he measurement of beta-galactosidase serves as a rapid and semiquantit ative assay of HSP70 gene activation. The Dunning cell clone showed ev idence of incorporation of the HSP70/beta-galactosidase construct with in the genomic DNA by Southern blot analysis. When compared to mock-tr ansfected control cells, the clone showed minimal baseline beta-galact osidase activity, which significantly increased following a hypertherm ic stress. The time course of beta-galactosidase elevation following h eat stress paralleled the time course of cellular HSP70 elevation by W estern blot analysis. These stably transfected Dunning R3327 cells may provide a useful tool to study the effects of hyperthermia, radiation , and chemotherapeutic agents on the cellular stress response and in t he establishment of HSP70 as a marker of cellular resistance in the mu ltimodal treatment of prostate cancer.